In this article, adding additional localized markup is supposed to help your site's SEO.

ie.

<div itemscope itemtype="http://data-vocabulary.org/Organization">
<span itemprop="name">Search Engine People</span>
<span itemprop="address" itemscope itemtype="http://data-vocabulary.org/Address">
<span itemprop="street-address">100 Westney Road South Unit 200, Building E</span>
<span itemprop="locality">Ajax</span>,
<span itemprop="region">ON</span>
<span itemprop="country-name">Canada</span>
<span itemprop="postal-code">L1S 7H3</span>
</div>

What about a site that contains valid localized results, where the actual business location is not relevant.

For example, a site with valid local results from San Francisco, CA and Phoenix, AZ. Should these tags be added to the localized results, and has anyone got any experience with how much adding these tags have improved results?

In terms of Google Places, however, they seem to ask for the business' actual physical location. Is there a way to use Google Places in the aforementioned example to assist in SEO?